use sed -r instead of -E when using GNU sed

[Un1q32]

sed -r and -E do the same thing, but sed -E is the portable version that works with all versions of sed, however some old versions of GNU sed only support -r, a workaround is to check if we're running GNU sed, and use -r if we are

[Un1q32]

bump

[catumin]

Built a version of GNU sed from before -E was added (I used 4.1.5, it was added 4.2), and then tested with that sed, my system's recent GNU sed, and macOS sed. All behaved as they should.

[Un1q32]

@BKasin can you try the latest commit, I reworked it into a wrapper function that replaces the arguements if sed is GNU sed, should be completely transparent so nobody has to remember to add $sed_ext to every sed command from now on

[catumin]

Will do.

[catumin]

Re-tested on previously stated platforms and can confirm the command gets rewritten properly based on GNU vs non-GNU sed. Screenshot shows that detection of GNU sed worked, and the ASCII art printing means that the sed on line 5222 works.

[hykilpikonna]

Nice fix, thanks!

And @BKasin thank you so much for the detailed testing!